Increasing maternal age is associated with taller stature and reduced abdominal fat in their children.

BACKGROUND: Maternal age at childbirth continues to increase worldwide. We aimed to assess whether increasing maternal age is associated with changes in childhood height, body composition, and metabolism. METHODS: 277 healthy pre-pubertal children, born 37-41 weeks gestation were studied. Assessments included: height and weight corrected for parental measurements, DEXA-derived body composition, fasting lipids, glucose, insulin, and hormonal profiles. Subjects were separated according to maternal age at childbirth: <30, 30-35, and >35 years. RESULTS: Our cohort consisted of 126 girls and 151 boys, aged 7.4 ± 2.2 years (range 3-10); maternal age at childbirth was 33.3 ± 4.7 years (range 19-44). Children of mothers aged >35 and 30-35 years at childbirth were taller than children of mothers aged <30 years by 0.26 (p = 0.002) and 0.23 (p = 0.042) SDS, respectively. There was a reduction in childhood BMISDS with increasing maternal age at childbirth, and children of mothers aged >35 years at childbirth were 0.61 SDS slimmer than those of mothers <30 years (p = 0.049). Children of mothers aged 30-35 (p = 0.022) and >35 (p = 0.036) years at childbirth had abdominal adiposity reduced by 10% and 13%, respectively, compared to those in the <30 group. Children of mothers aged 30-35 years at childbirth displayed a 19% increase in IGF-I concentrations compared to offspring in <30 group (p = 0.042). Conversely, IGF-II concentrations were lower among the children born to mothers aged 30-35 (6.5%; p = 0.004) and >35 (8.1%; p = 0.005) compared to those of mothers aged <30 years. Girls of mothers aged 30-35 years at childbirth also displayed improved HOMA-IR insulin sensitivity (p = 0.010) compared to girls born to mothers aged <30 years. CONCLUSIONS: Increasing maternal age at childbirth is associated with a more favourable phenotype (taller stature and reduced abdominal fat) in their children, as well as improved insulin sensitivity in girls

Summary of the study's recruitment process.

<p>¹ OS_A children had been conceived via ovarian stimulation, and were examined in Savage <i>et al. </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058869#pone.0058869-Savage1" target="_blank">[13]</a>. ² Controls were friends of OS_A children to ensure similar age group, ethnicity, and socio-economic status. ³ 22 children were born small-for-gestational age and/or premature; 5 were pubertal; 3 were born to a mother with gestational diabetes/glucose intolerance; and one child was on medication known to influence growth.</p

Height and BMI SDS corrected for mean parental height and mid-parental BMI SDS, respectively, among the offspring of mothers of different ages at childbirth.

<p>Data are estimated marginal means and 95% confidence intervals, adjusted for other confounding factors in multivariate models (including paternal age). *p&lt;0.05 and **p&lt;0.01 vs children of mothers aged &lt;30 years at childbirth. Abdominal adiposity is represented by the android fat to gynoid fat ratio. The 95% confidence intervals for the differences between groups are provided in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058869#pone.0058869.s001" target="_blank">Table S1</a>.</p

Lipid and IGF profiles in childhood according to maternal age at childbirth.

<p>Data are estimated marginal means and 95% confidence intervals adjusted for other confounding factors in the multivariate models (including paternal age). *p&lt;0.05 and **p&lt;0.01 vs children of mothers aged &lt;30 years at childbirth. The 95% confidence intervals for the differences between groups are provided in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058869#pone.0058869.s001" target="_blank">Table S1</a>.</p

Parameters of glucose homeostasis among boys and girls according to maternal age at childbirth.

<p>Data are estimated marginal means and 95% confidence intervals adjusted for other confounding factors in the multivariate models (including paternal age). ^*p&lt;0.05 and ^**p&lt;0.01 for comparisons with &lt;30 group. The 95% confidence intervals for the ratios between estimated marginal means are provided in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058869#pone.0058869.s002" target="_blank">Table S2</a>.</p

Distribution of maternal age at childbirth in the study cohort.

<p>Distribution of maternal age at childbirth in the study cohort.</p